PEOPLE travelling by train from Clitheroe, Blackburn and Darwen to Manchester will have to continue catching buses from Bolton to Victoria Station for a further two months.

A complex tunnelling project to enable electric trains to run between Bolton and Manchester has been delayed, possibly until December, by exceptionally poor ground conditions.

It had been hoped to complete the scheme next month. It is part of an upgrade to the line from Clitheroe, via Blackburn and Darwen, to Victoria to speed trains and allow the introduction of the every 30-minute service in December 2016.

Network Rail engineers enlarging the 1834-built Farnworth Tunnel south of Bolton have run into large swathes of sand. Rather than having a firm material to bore through, sand is pouring down into the excavated area halting progress.

It has proved impossible to safely excavate while concurrently installing and grouting sections of tunnel wall as originally planned.

Engineers are now pumping resin into the ground to firm it up before nine metre-wide ‘Fillie’, the UK’s largest tunnelling machine, bores through it.

Martin Frobisher, from Network Rail, said: “This delay is intensely frustrating for our engineers and, more importantly, for passengers who are set to benefit from more frequent, faster, quieter services once this wider programme of work is complete.

“We are doing the best we can in difficult circumstances and we are sorry it is taking longer than we first thought and impacting on passengers.

“We first hit an area of running sand on August 14 when our engineers saw it suddenly pouring from the working face. The nature of civil engineering, especially deep below ground, is that you never fully know the exact ground conditions until you start tunnelling or excavating.

Alex Hynes, managing director for Northern Rail, said: “We are deeply disappointed that work to deliver the Farnworth Tunnel project will now not be completed by October 5.”